Pattern control device for textile tufting machines



June 4, 1968 R. ELLISON ET AL 3,386,397

PATTERN CONTROL DEVICE FOR TEXTILE TUFTING MACHINES Filed Dec. 16, 1965 INVENTORS RONALD ELL 150M JOHN PR HARP ikdm 4 TTORNE) United States Patent 3,386,397 PATTERN CONTROL DEVICE FOR TEXTILE TUFTING MACHINES Ronald Ellison and John Pritchard, Blackburn, England,

assignors to Ellison Tniting Machinery Limited, Blackburn, England Filed Dec. 16, 1965, Ser. No. 514,331 Claims priority, application Great Britain, Mar. 30, 1965, 13,366/ 65 1 Claim. (Cl. 11279) ABETRACT OF THE DISCLOSURE An opaque flexible endless pattern band travels on a pair of spaced rollers. A row of photo-sensitive devices is mounted in a bar arranged transversely to the bands path adjacent the bands outer face. Lamps are mounted above the respective photo-sensitive devices and the light from these is transmitted by a bent transparent bar to the pattern. The light is reflected from the pattern to the photosensitive device through a small hole in the bar.

Our invention relates to tufting machines for making carpets and like textile articles, and has for its object the provision of means for producing a pattern effect. The said etlect consists in the production of tuft loops of difierent lengths on a backing material, and may include the production of a coloured pattern. A machine of this type is illustrated in United States No. 2,862,465 to which reference is made insofar as is necessary for an understanding of this invention.

It is known to provide each yarn or a group thereof with an individual control for affecting the length of each loop made by the needles, the control being derived by a photocell provided for each yarn or group, a row of such cells being located on one side of a translucent drum having an opaque pattern thereon, with a light source inside the drum, which is rotated at a predetermined rate relative to the photocells so as to control the tufts produced in accordance with the pattern. This arrangement has the disadvantages that the pattern drum must be shielded from room light, and that the energy falling on each photocell is relatively small.

We propose to avoid or reduce such disadvantages by using reflected light to control the pattern making mechanism. In one embodiment of our invention, a pattern is drawn in black on white opaque paper or similar material in the form of a strip, and the pattern is laid on and fixed to a rotatable drum, or joined end to end to form a band. The drum or band is located under a unit comprising lamps and photocells, the lamps being arranged in a row, the light from the lamps being directed so as to illuminate a broad band which is the whole width of the pattern. The photocells are arranged in either a single line or in a staggered form close to the lamps but shielded therefrom, the said shield being so formed as to allow each photocell to pick up light from an area of the pattern corresponding to a single stitch of the tufting mechanism. An additional light shield may be provided to cover the pattern in the region of the light band so as to prevent the photocells from being influenced by ambient or room light.

The output of each photocell is amplified and preferably passes through a trigger circuit so that the amplifier output is either on or off, without any intermediate value. The output of each amplifier is connected to a loop length controlling device which may for example be a pneumatically operated brake shoe acting on one or more of the yarns forming the carpet pile.

Preferably the lamp-photocell unit is made in the form of a drilled bar. The said bar extends across the whole "ice width of the pattern, and contains a row of drillings, with lamp mountings on the bar.

The drillings are holes each of which consists of borings of two diameters, the top bore of which may extend halfway through the bar and is of sufficient size to accommodate a photocell in its holder. From this boring, a boring of smaller diameter continues through the bar in the direction of the pattern, so that each photocell sees only a portion of the pattern corresponding to a single stitch to be made by its associated needles. The bar is preferably made so as to be easily withdrawable, so that defective lamps or photocells can be readily tested or replaced. The bar may carry at its lower end a light shield formed so as to embrace a suflicient area of the pattern as to prevent room or incident light from falling on that part of the pattern illuminated by the lamps, which are mounted in light-conducting supports on the bar.

When the machine is in use the pattern is driven at a rate corresponding to the rate at which the tufting needles engage the backing material, and the pattern may be indefinitely repeated.

The outputs of the amplifiers may be connected to the needle control mechanism in such manner that each photocell controls a plurality of needles, and the control may be reversible, so that for instance a dark part of the pattern may, under one condition, cause the production of a long tuft and under another condition may produce a short tuft. In order to produce a coloured pattern some of the needles may be fed with yarn of one colour and the remaining needles with a yarn of another colour.

Reference should now be made to the accompanying drawings in which:

FIGURE 1 shows a form of our invention more particularly suited to the production of a reversible pattern, or one of extended length, and

FIGURE 2 is a section of the photocell-lamp unit.

In the form shown in FIGURE 1, the pattern drum, previously envisaged as of at least several inches in diameter, is replaced by two smaller rollers carrying the pattern in the form of a band.

The pattern band 1 has a pattern drawn on it, and is carried by a roller 2 driven by a motor 3. This motor is of the synchronous or "Magslip type, and operates in step with the backing material feed drive. The roller 2 has a series of teeth 4 round one end, these engaging with holes 5 punched along the edge of the pattern band. This band is maintained under tension by a dancing roller 6, the end bearings 7 of which slide freely in parallel vertical guides (not shown), and the band is maintained in position by passage over a smooth plate 14. The band is provided with edge marks 8 defining the extent of a pattern repeat.

The lamp and photocell assembly is of the form shown in FIGURE 2. It is mounted by means of supports 11 on a bar 12, so that the whole assembly can be swung out of position with respect to the pattern, for testing or replacement of components. The assembly is provided at each end with rollers 13, these resting on the pattern during use of the device, to give correct spacing.

A bar 10 of aluminium or light alloy is drilled with a series of holes of which one is shown at 15. This hole is drilled only part way through the bar, and is large enough to take a phototransistor or photocell 16. A smaller hole continues from the first drilling so that the photocell can see a small part of the pattern 1 corresponding to one stitch length.

Each lamp 18, preferably of the pre-focussed type, is mounted on a support 19. This is clipped to a bent bar 20 of transparent material, the lamp being located in a hole 21 in the bar so that light from its filament traverses the bar and emerges from the end 22 to fall on the pattern 1 from which it is reflected into the hole 17.

The assembly is provided with light shields 23. This form of assembly, with the lamps well away from the photocells, prevents heat from the lamps from alfecting the characteristics of the photocells.

The lamps are lit in parallel from a source of current, and the photocell outputs are connected to individual amplifiers terminating in flip-flops, the latter operating relays which control the patterning effect of the needles.

The spots 8 are located so as to atTect a photocell provided to give a signal to the main control mechanism when a predetermined amount, or the whole, of the pattern has passed beneath the photocell-lamp assembly. Passage of a spot may cause a change of loop length or a change of colour, or a reversal of the pattern.

If necessary, optical means such as spherical or cylindrical lenses may be employed to concentrate the light from the lamps on a small part of the pattern.

We claim:

1. In a tufting machine for producing patterned carpet and like fabrics by inserting tuits of yarn in a backing fabric said tufts being of different lengths to form said pattern, a control device for said machine comprising an opaque flexible pattern band, a pattern to be copied by said machine on one face of said pattern band, a toothed driven roller for supporting and driving said band, means for driving said roller at a speed commensurate with the speed of transit of said backing fabric through said machine, a dancing roller supported by said pattern band, an assembly comprising a bar for housing a plurality of phototransistors in a row, and lamps, light-conducting rod means secured to said bar and having one end of said rod in close proximity to said patterns band for conducting the light from said lamps to said patterned face, shield means for enclosing said one end and said phototransistors to prevent ambient light from influencing said phototransistors, means for locating said assembly near said patterned face to that light reflected therefrom affects said phototransistors, and means connected to the outputs of said phototransistors for controlling the length of yarn supplied by the needles of said tufting machine during each stitch.

References Cited UNITED STATES PATENTS 2,231,494 2/1941 Dickinson 250227 X 2,432,793 12/1947 Payne 250227 X 3,103,187 9/1963 Hammel 1l279 3,105,152 9/1963 Nash 250-2l9 3,106,706 10/1963 Kolanowski 250227 X 3,188,478 6/1965 Binks 250-219 3,272,163 9/1966 Erwin l1279 3,294,050 12/1966 Corley et a1 11279.6

FOREIGN PATENTS 142,290 1/1961 U.S.S.-R.

HERBERT F. ROSS, Primary Examiner. 

